I dont understand what do you mean by 'not keeping count' of which gear you are in. Tell me something.......in a manual car, how do you know which gear you are in? Or in any other triptronic car how do you know which gear you are in? Does accord/markx speaks to you which gear it is in? Big NO
I have driven in triptronic without the need to see the instrument cluster to know which gear I was in. It takes a little practice and you are all set to go, and this is with triptronic cars.
As far as driving in D vs triptronic is concerned, it all depends on the drivers preference. Personally I drive in D (thats why I bought an automatic car, so that I dont have shift gears) but sometimes when I have to drive fast or when I am in mood for some fun, I shift into S and change gears at my own will